LIMIT 和 OFFSET 过滤数据库结果的问题（语法错误）

Question

我正在尝试创建一个页面，用户可以在其中搜索书籍，他们可以输入书名和作者 - 这是可选的，还可以输入返回列表的起始位置和列表的长度。然后应返回包含详细信息的书籍列表。

当我尝试运行使用 print_r($stmt->errorInfo()); 的代码时，我收到错误：

You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ' authors = '' LIMIT '2' OFFSET '0'' at line 1 )

主要代码如下：

$title = $_GET["title"];
$authors = $_GET["authors"];
$start = (int)$_GET["start"];
$length = (int)$_GET["length"];

$sql = "SELECT title, authors, description, price
FROM book2
WHERE title LIKE '$title%' 
AND author LIKE '%$authors%'
OFFSET 0,$start
LIMIT 0,$length";
$stmt = $dbh->prepare($sql);
$stmt->bindParam(':title', $title);
$stmt->bindParam(':authors', $authors);
$stmt->bindParam(':length', $_GET['length'], PDO::PARAM_INT);
$stmt->bindParam(':start', $_GET['start'], PDO::PARAM_INT);

     $stmt->execute(array(

    ':title' => $title,
    ':authors' => $authors,
    ':start' => $start,
     ':length' => $length   
      ));

print_r($stmt->errorInfo());

echo "<table>";
while ($row = $stmt->fetch(PDO::FETCH_ASSOC))
{
$title = $row['title'];
$authors = $row['authors'];
$description = $row['description'];
$price = $row['price'];

echo "<tr>";
        echo "<td>Title</td>";
        echo "<td>$title</td>";
echo "</tr>";
echo "<tr>";
        echo "<td>Authors</td>";
        echo "<td>$authors</td>";
echo "</tr>";
echo "<tr>";
        echo "<td>Description</td>";
        echo "<td>$description</td>";
echo "</tr>";
echo "<tr>";
        echo "<td>Price</td>";
        echo "<td>$price</td>";
echo "</tr>";
}
echo "</table>";

我不确定错误是什么我如何让这段代码工作？我希望这个方法是正确的，因为我无法测试它。

Answer 1

您应该只使用 LIMIT：

$sql = "SELECT title, authors, description, price
FROM book2
WHERE title LIKE '$title%' 
AND author LIKE '%$authors%'
LIMIT $start,$length";

OFFSET 的语法仅出于兼容性原因：

For compatibility with PostgreSQL, MySQL also supports the LIMIT row_count OFFSET offset syntax.

LIMIT 的有效示例如下：

LIMIT offset, row_count
LIMIT row_count
LIMIT row_count OFFSET offset

Answer 2

$sql = "SELECT title, authors, description, price
FROM book2
WHERE title LIKE '$title%' 
AND author LIKE '%$authors%'

顶行显示 authors，底部显示 author。由于提供的错误，我会说 author 是正确的，你应该删除 authors

中的 s

虽然检查了 cascaval 关于限制的答案。修复 author 后，您的代码中可能会出现第二个错误，而 cascavals 的答案应该可以帮助您解决这个问题。

LIMIT 和 OFFSET 过滤数据库结果的问题（语法错误）

Problems with LIMIT and OFFSET to filter database results (error in syntax)

php

mysql

pdo

limit

offset